NEWS ABOUT SCIENCE, TECHNOLOGY AND ENGINEERING
AT IOWA STATE UNIVERSITY

AMES, Iowa --

Making meat safe from contamination

A new way to detect fecal contamination on fresh meat could
help industry meet safety regulations designed to control
disease-causing bacteria. Using laser-induced fluorescent
spectroscopy, Iowa State University Associate Professor of
Chemistry Jacob Petrich and Agricultural Research Service
microbiologists Mark Rasmussen and Tom Casey, have built a
detector that illuminates fecal contamination on meat.
Petrich says the device is adaptable to any size packing
plant. As a hand-held unit, similar to metal detectors used
in airports, the instrument could alert meat packers to fecal
contamination in seconds. The contaminated meat fluoresces,
or "glows," in a specific color for easy determination of
contamination. The contaminated carcass then could be
sanitized before the contamination spreads.

Feces are a major source of bacterial contamination in
livestock and poultry slaughterhouses, according to
Rasmussen. After a 1993 E. coli outbreak in the Pacific
Northwest, the USDA developed new sanitation requirements for
slaughterhouses, including stiffer inspections for fecal
contamination and tests for E. coli. According to Casey,
these have not been easy tasks to accomplish with present
visual inspection methods.

With the new technology, the inspection job will be easier,
faster and more accurate. The ISU/ARS research is timely
because the USDA's Food Safety and Inspection Service is
enforcing zero-tolerance standard for fecal contamination on
livestock and poultry carcasses. The researchers are
patenting their technology and discussions are under way with
industry on commercial development. Contact Petrich at (515) 294-9422, or
Skip Derra, News Service, (515) 294-4917.

Twinkle, twinkle diamond star

A team of about 50 astronomers are training their telescopes
on a relatively close pulsating white dwarf star with the
goal of possibly finding a true gem in the sky. The
astronomers, led by Steve Kawaler, an Iowa State University
professor of physics and astronomy, will be monitoring a
vibrating white dwarf star designated BPM37093, which is 17
light years from Earth. (A light year is the distance light
travels in a year, about 6 trillion miles.)

The astronomers are making their observations using the Whole
Earth Telescope and the Hubble Space Telescope from April 17
to May 4. Their findings could have an impact on the age of
our galaxy and the universe, and become the delight of
gemologists worldwide.

"We think BPM37093 is primarily made up of carbon and oxygen
in a crystallized state," Kawaler says. "That would make it a
diamond with a blue-green tint. It's estimated carat weight
is 1034, or 10 billion trillion trillion. This truly could be
a diamond in the sky."

BPM37093 is a slowly cooling remnant of a star that once was
a little more massive than our Sun. It resides in the
constellation of Centaurus and is clearly viewable only from
the Southern Hemisphere. Understanding the properties of
white dwarf stars is important because nearly all stars will
become eternally cooling white dwarf stars. Only the most
massive stars will become fiery exploding supernovas. By
measuring the vibration frequency of BPM37093, astronomers
can sneak a peak into its interior. Through stellar
seismological techniques, Kawaler and the team of astronomers
will attempt to ascertain the makeup of BPM37093.

"The pulsations will tell us what's going on inside a star
the same way earthquakes tell us about the inside of Earth,"
Kawaler said. Contact Kawaler at (515) 294-9728, or Skip Derra, News
Service, (515) 294-4917.

Conference updates virtual reality

Fire up the rear-projection screens and strap on the data
gloves, virtual reality techies from all over the world will
be coming to Ames May 11 and 12 to discuss alternate
realities during the Second International Immersive
Projection Technology Workshop (IPT98). The conference will
be held in the Scheman Building and while the topics will be
technical in nature, they also are expected to be visual.

"Virtual reality is very visual so you can expect a lot of
presenters to include videos of their work," says Carolina
Cruz-Neira, Litton assistant professor of electrical and
computer engineering and conference chair. The program will
cover a range of topics, including screen configurations,
projection algorithms, software architectures, applications
and networking. IPT98 is a forum to present current research
and development activities using projection technology for
virtual reality. VR researchers from Germany, Japan, and
major practitioners in the U.S. will be making presentations
on topics ranging from large-scale immersive displays in
entertainment and education to the limits of human vision.

The conference is being hosted by Iowa State's Iowa Center
for Emerging Manufacturing Technology and the Fraunhofer
Institute For Industrial Engineering, Stuttgart, Germany.
Other sponsors include Silicon Graphics Inc., Mountain View,
Calif., and Engineering Animation Inc., Ames, Iowa. For more
information on the conference call the ICEMT office at (515)
294-3092, or check the web site at
http://www.icemt.iastate.edu/ipt98. Contact Cruz-Neira at (515) 294-4192,
or Skip Derra, News Service, (515) 294-4917.

Casting tools

Use of castings -- monolithic, poured metal parts that
replace a number of smaller components -- can improve a
product while saving money by reducing inventory tracking and
the need for assemblies. For example, an aircraft door frame
could use one casting to replace more than 100 parts. But
castings occasionally have pores or inclusions that diminish
the component's strength. In order to ensure safety, the
weight of the material used may be increased to compensate
for the pores and inclusions, but this is often an
unsatisfactory and expensive solution.

Now, scientists from Iowa State University's Center for
Nondestructive Evaluation (CNDE) are taking a different
approach. They are developing tools to help industry
determine the types of defects that compromise safety, devise
the best plan for inspection and gain a better understand of
casting.

CNDE's Joe Gray is working with other researchers to develop
a model that can be manipulated to determine what types of
defects will occur, the type of defect likely in safety-
critical areas, the size of defect that will compromise
safety and the testing technique required to locate the
defect in a given part. The model will also allow industry to
determine how new materials will behave without extensive and
expensive testing of large numbers of samples. The tools hold
potential for a number of industries, including automotive
and aircraft manufacturers. Contact Gray at (515) 294-9745, or Anita
Rollins, IPRT Information, (515) 294-1113.